1. Field of the Invention
The present invention relates to tape transports. More specifically, the present invention is directed to a tape reel brake for a tape transport.
2. Description of the Prior Art
On tape recorders, tape reel brakes are used to prevent excessive spilling of tape in the event of power failure or other loss of control over a tape spooling operation. As the tape is spooled from one reel to another the effective reel diameter, i.e., the height of the wound tape, changes. The conventional constant brake torque generating reel brake, consequently, provide a compatible braking effect for only one effective reel diameter, i.e., the braking effect is either excessive or insufficient for other effective reel diameters. Additionally, conventional tape reel brakes employ some sort of differential braking that is dependent on reel rotation to provide a trailing reel with a higher brake torque than the leading reel although also with only a fixed or constant braking effect. The inherent problem with this conventional approach is that it cannot compensate for the change in momentum during the change in the amount of tape on the tape reel, i.e., a full reel of tape has considerably more momentum than an empty one so that it needs more brake torque to stop in the same time as an empty tape reel. Accordingly, it would be desirable to provide a reel brake which maintains the characteristic of differential braking torque but that it also provides a braking torque that is dependent on the difference in a momentum of the tape reels as the tape is removed and added therefrom.